guides on the internet. in november, rhode island police arrested this man who learned how to make a chemical soup to rub off ink on $5, turning them into fake 100s. he maintained he is innocent. >> if the consumer takes the time to match the watermark and knows it doesn't match the portrait, they would know something was wrong with the bill. >> reporter: the government says new security features do help. >> if you take the note and tilt it back and forth, you will see the 100 in the lower right corner, actually shifts from copper to green. >> reporter: now is a good time to take a closer look at the money in your pocket. steve osunsami, abc news, atlanta. >> wow. go ahead. >> it says, you know, we have learned that if you handle money regularly, it is likely you have passed at least one fake bill. remarkable. apparently, the fake bills, i have touched them. they do feel a little slicker than, than others. >> there is a certain feel to it. they say a tutorial on detecting counterfeit currency, on the website of the treasury department and secret service if you want to do investigating. >> let me touch it. >> i rarely carry cash, check out this $10 bill. >> let me touch it. >> is it real? >> i am not sure.